1. Technical Field
The present invention relates to an improvement of a fuel filter disposed in a fuel tank for automobiles in such a way as to be soaked in fuel, more particularly to a fuel filter capable of preventing a filter cloth from being damaged.
2. Prior Art
There are various kinds of fuel filters for catching foreign matters in fuel, of which the fuel filter disposed in a fuel tank in such a way as to be soaked in fuel is known.
A known fuel filter disposed in a fuel tank will be described with reference to FIGS. 9 and 10.
The known fuel filter 1 disposed in a fuel tank comprises a bag-shaped filter cloth 2, a frame body 4 for supporting the filter cloth 2 so as to partition the filter cloth 2 to form inner spaces 3 therein and an outlet pipe portion 5 for discharging fuel. The outlet pipe portion 5 is connected to a suction port of a fuel pump 6 through which fuel is supplied to a carburetor or a fuel injection unit, not shown. The fuel filter 1 and the fuel pump 6 are disposed in the fuel tank 7 at the portion adjacent to a bottom of the fuel tank 7.
The frame body 4 employed by the fuel filter 1 must have the following functions.
Since the fuel filter 1 catches foreign matters in the fuel passing through the filter cloth 2, it must have inner spaces 3 for containing fuel therein. Accordingly, the frame body 4 must have a shape adapted for contacting the filter cloth 2 and swelling the filter cloth 2 so as to form the inner spaces 3 therein.
Since the known fuel filter I disposed in the fuel tank 7 for automobiles must suck all the fuel from the fuel tank 7 (although a small amount of fuel is residual in the bottom thereof), it must be disposed in the fuel tank 7 so as to contact the inner bottom wall thereof.
To carry out the aforementioned functions, the known frame body 4 comprises a bottom wall member 4A disposed in contact with the inner bottom wall of the fuel tank 7 and a plurality of rising wall members 4B which project from both ends of the bottom wall member 4A so as to suck all the fuel in the fuel tank 7 and partition the filter cloth 2 to form inner spaces 3.
However, this known fuel filter 1 has the following drawbacks.
Since the frame body 4 is bent at corners 8 provided at the rear surface of the bottom wall member 4A which contact the filter cloth 2 with a given angle, namely, the corners 8 of the frame body 4 are pointed, the filter cloth 2 swings when the fuel swings in the fuel tank 7 so that the filter cloth 2 is liable to be broken by the corners 8. That is, since the corners 8 provided at the rear surface of the bottom wall member 4A are pointed at the portion contacting the filter cloth 2, the filter cloth 2 is liable to be broken when the filter cloth 2 is swung and repeatedly pressed against the corners 8.
Furthermore, since corners 9 which are provided at the bottom wall member 4B and contact the filter cloth 2 are also pointed, the filter cloth 2 are likely to be damaged when the filter cloth 2 is repeatedly pressed against the corners 9.
Still furthermore, since the frame body 4 is formed of a rigid body, it is not flexible, the contact pressure between the filter cloth 2 and the corners 8 is increased when the filter cloth 2 contacts the corners 8, which aggravates the damage of the filter cloth 2.
Still more further, since the rising wall members 4B are square, the wall members 4B contacting the filter cloth 2 have small contact areas so that the filter cloth 2 is liable to become deflated by this contact areas since gaps are defined between the wall members 4B and the filter cloth 2.